Localization and delocalization of ultracold bosonic atoms in finite optical lattices

Abstract

We study bosonic atoms in small optical lattices by exact diagonalization and observe a striking similarity to the superfluid to Mott insulator transition in macroscopic systems. The momentum distribution, the formation of an energy gap, and the pair correlation function show only a weak size dependence. For noncommensurate filling we reveal in deep lattices a mixture of localized and delocalized particles, which is sensitive to lattice imperfections. Breaking the lattice symmetry causes a Bose-glass-like behavior. We discuss the nature of excited states and orbital effects by using an exact diagonalization technique that includes higher bands.

8 pages, 10 figures. Published version

References in corpus (3)

• Quantum phase transition from a superfluid to a Mott insulator in a gas of ultracold atoms
• A lattice of double wells for manipulating pairs of cold atoms
• Imaging the Mott Insulator Shells using Atomic Clock Shifts

Cited by in corpus (8)

• Cold Bosons in Optical Lattices
• Self-Trapping of Bosons and Fermions in Optical Lattices
• Stochastic Mean-Field Theory for the Disordered Bose-Hubbard Model
• Controlled generation of coherent matter-currents using a periodic driving field
• Interaction Driven Interband Tunneling of Bosons in the Triple Well
• Finite-size effects in Anderson localization of one-dimensional Bose-Einstein condensates
• Equilibrium and Disorder-induced behavior in Quantum Light-Matter Systems
• Excitation spectrum of Mott shells in optical lattices